Trolling motor lost thrust?

[jyarbro7]

I just got two brand new optima yellow top deep cycle batteries for my motorguide 71 lb thrust trolling motor. I charged the batteries up and hooked all the wires like they're supposed to be and it is noticeable that there is a lack of power compared to my old blue tops. The old ones had to be replaced because of dead cells. They did have a larger capacity than the new yellow tops, but I didn't think that would cause my motor to lose thrust, I though it just wouldn't be able to run as long as before. Any suggestions?

[CatFan]

Check your wiring. Mixed cables could mean you only have 12V at the motor. Measure the voltage at the bow plug. You should see 26V.

[jyarbro7]

Will do

[billnorman1]

A voltage check is important. Are you testing it in the water or out? You may have a new defective or uncharged battery. You should not have any different speed from any size battery when new, just long term.